Drilling machine



Jan. 16, 1923.

:z. I. mom.

DRILLING MACHINE.

FILED 025.13. I9I8.

Jan. 16, 1 923.

4 H. J. HJORTH.

DRILLING MACHINE.

2 SHEETS-SHEET 2.

FILED 9-3018. 1918.

Patented Jan. 16, 1923.

UNITED STATES HENRIGK J. HJ'ORTH, OF WOIBURN, MASSACHUSETTS.

DRILLING MACHINE.

Application filed December 18, 1918. Serial No. 267,302.

To all whom it may concern:

Be it known that L'HENRICK J. HJORTH, a citizen of the United States, residing at Woburn, in the county of Middlesex and State of Massachusetts, have invented new and useful Improvements in Drilling Machines, of which the following is a specification.

The present invention relates to machines analogous to drill presses, and has for its objects the following among others :to enable 3. long and slender tool, such as a twist drill of. familiar type, orother analogous tool to be employed for forming deepholes of small diameter without sensible deviation from a straight line; to effect drilling operthereof and equivalents as pointed out in the appended claims.

In the drawings forming a part of this application and illustrating the preferred structures embodying the principles of my invention, Figure 1 is an elevation of a conventional drill press having the improvements constituting my invention applied thereto; said improvements being shown in section. Figure 2 is an elevation of the drill holder containing certain features of the invention. Figure 3 is a plan view of the upper end of the holder shown in Flg -ure 2. Figure 4 is an under plan view of the lower end of the said holder. Figure 5 is an under plan view of the work holder shown in Figure 1, as viewedfrom line 5-5 of that figure looking upward. Figure 6 is an elevation of the said work holder. Figures 7 and8 are detail views of a modified form of work holder. Figure 9is a perspective view of the parts shown in Figures 7 and 8. Figure 10 represents in plan and longitudinal section the gripping sleeve shown in Figures 7 and 9. Figure 11 is 'an elevation of a gripping sleeve forming partof the combination embodied in the drill holder represented in Figures 2 and 3.

Like reference characters designate the same parts in all the figures.

Referring to Figure 1, 11 represents the base, 12 the column, and 13 the head of a drill press. 14 is an arm projecting laterally from the head 13 and having a guide 15 in which there is movable endwise a slide 16, the latter providing a bearing in which is contained the rotatable spindle 17 The spindle turns also, and is movable endwise, in a bearing 18 on the head, and is engaged with a bevel gear 19 in mesh with a complemental gear 20 which is secured to a transmission shaft 23. The latter shaft carries a step pulley 24 driven by a belt 25 from a driving step pulley 26 on a countershaft which is mounted in a bracket 27 fixed to the machine base; said shaft having fast and loose pulleys 28 and 29 adapted to receive a driving belt driven from some source of power. 30 represents a lever having suitable engagementwith a pinion 31 which meshes with teeth 32 on the slide 16, and is operable to raise and lower the slide, and therewith'the spindle 17. Such spindle is so engaged with the slide 16 that it may rotate therein but may .not be displaced endwise relatively thereto, while its engagement with the gear 19 is such that it is rotated positively by the latter, but may move endwise relatively thereto. 33 is a chain or equivalent connector which passes from a point of attachment to "the.slide 16 into a channel within the head 13 and thence into the hollow interior of the post 19, a weight being attached to the chain to counterbalance to the desired degree the. weight of slide 16, spindle 17, and the parts carried by the. latter. The chain passes over a pulley'within the head mounted on a pin'34. 35 is an arm having a split hub 36 formed with wings 37 flanking the line Where it is cut orsplit, and containing a clamping screw 38 having a handle 39. The arm is thus adapted to be adjusted along the post or column 11 and secured in any desired position. I

The machine as thus far described is a previously known type of drill press represented to illustrate the type of machine to which the particular invention hereinafter described and claimed may be applied. Improvements which I have invented comprise the following. Instead of mounting the drilling toolon the rotating spindle, as is the usual practice, I have provided means for mounting it in an immovable manner on the arm 35, the latter being normally stationary and constituting a stationary toolholder. 41 represents the active tool, here shown as a twist drill of common type secured in a holder 42, the latter being contained in a sleeve 43 which is detachably mounted on the arm 35. A convenient means for thus mounting the sleeve 43 consists in forming upon the arm a tubular part similar in character to the hub 36, which is slotted or split at one side and carries wings 44 at opposite sides of the slot adapted to be drawn together by screws and nuts, or screws alone, so as to grip the sleeve. The holder 42, in which is embodied certain claimed features of the invention, is tapered and fits the complementally tapered bore of the sleeve 43. Its lower end protrudes from the lower end of the sleeve and is provided with a square, or at least a non-circular part 45 shown in Figures 2 and 4 which so fits a complemental hole in a disk v46 that it can not turn therein, and such disk is secured rigidly to the sleeve by screws 47. The extreme end of the holder is turned and threaded in the part 48 and receives a nut 49 which bears against the disk 46 and thus is adapted to draw the holder into such tight engagement with the sleeve as to prevent vibration of the holder and also to prevent leakage of liquid between the contacting surfaces of the holder and sleeve. The upper end of the holder is made with a socket which is entered by the shank of the drill 41 and is slotted in a manner which divides the walls of the socket into springy jaws which are adapted to be closed in upon the drill shank to grasp it. There may be one, two, or more slots according 'to circumstances and as needed in order to form'resilient clamping jaws. A separate ring 50 surrounds this end of the holder, and therein are mounted set screws 51 arranged to bear upon the said jaws and to press them against the drill shank. Said holder thus constitutes a chuck. As a convenient detail of manufacture I prefer to make the socket in this chuck of such dimensions that it will fit the largest size of drill which may be used in the machine, and the jaws will bear directly against the shank of such drill; while for accommodating drills of smaller size, I provide lining sleeves, one of which is shown in Figures 2 and 11 and designated 52, and all of which are alike except as to specific dimensions. These lining sleeves all have the same external diameter to fit the socket in the holder, but are of different internal diameters to fit drill shanks of different sizes. Each sleeve is also partially subdivided by one or more slots 53 to form jaws adapted to be pressed against the drill shank by the pressure of set screws 51 applied through the jaws of the holder.

Sleeve 43 is provided nearits upper end with a horizontal flange 54, upon which is mined by an overflow pipe 58 having a telescopic extension sleeve 59 which is adapted to be raised and lowered Any receptacle may be placed to receive the discharge from the overflow pipe, but I have provided a permanent tank 60 mounted on the base 11, and used in connection with a circulating system.

An additional outlet normally closed by a removable plug 58 is provided for emptying the tub without disturbing the adjustment of the overflow whenever desired, as when it becomes necessary to substitute a difi'erent drill from that previously mounted.

The circulating system here referred to embraces a. pump 61 driven from the pre-' viously described countershaft by pulleys 62,

63 and a belt 64, or from any other source of power by other means; said pump drawing liquid from the tank 61 and delivering itto a pipe 65 which joins a nipple 66 screwed into the end of the holder 42. Said holder has a passage 67 running from the nipple to the socket-in which the drill shank is contained and preferably the shanks of the several drills are each formed with a passage 68 in continuation of the passage 67 and having a discharge orifice from one of the flutes of the drill as shown at 69 in Figure 2. By

this circulating means the liquid in the tub may be keptup to the level established by the adjustable overflow pipe, and furthermore so applied as to lubricate the drill and wash out chips from the hole being drilled.

71 represents the workpiece which is mounted in a chuck secured to the spindle 17. vOne form of such chuck is shown in Figures 1, 5, and 6, and consists of two plates or disks 72 and 73 secured together by screws 74. One of the plates has a cylindrical lip 75 slotted to form spring jaws which are surrounded by a ring 76having set screws 78 for causing such jaws to grip the spindle; The other plate has similarly formed jaws 79 surrounded by a, ring 80 which carries set screws 81. This construction of chuck. is thus adapted to be secured frictionally to the, spindle and to hold the work piece frictionally, and is made of separable units. Similar units interchangeable with one another and difi'ering only in the internal diameters of their jaws may be provided in such numbers and sizes as to fit the spindles of all drill machines and workpieces of all sizes, whereby 'to fit up readily any existing machines to treat workpieces of different dimensions. These plates are readil separable from one another, whereby the p ates 73 associated with jaws of different internal diameters may be connected to the same plate 72 in order to accommodate workpieces of different sizes. That is, whereas there need be only enough of the plates 72 with their jaws75 of appropriate diameters to fit-the spindles of whatever number of drills may be at hand, there may be as many plates 73 with jaws 79 of different widths as there are sizes of workpieces, all of the plates 73 being interchangeable with one another in connection with the plates 72. To secure accurate centering of the sets of jaws when, plates are thus interchanged, one of the plates, as 72, is provided with a shallow recess, preferably concentric with the axis, the bounding rim of which fits accurately the periphery of a complemental rojection on the other plate or the circumference of the plate itself if desired.-

A modified form of work holding chuck is shown in Figures 7, 8, 9 and 10 and consists of a sleeve 83 adapted at one end to slip over the end of the spindle 17, being slotted at that end to form jaws, and having a surroundin ring 84 fitted with set screws 85 for setting up these jaws'against the spindle. The other end of the sleeve is cut in two on a diameter and one side is entirely severed, forming thereby an integrally united semicylindrical part 86 and a separate complemental semicylindrical part 87. The reason ,for making the part 87 entirely separable from the balance of the sleeve or holder is to enable long workpieces to be put in place more easily than would be possible if the holder were made with resilient connected lower jaws adapted to have the workpiecesinserted endwise between their ends. piece in this manner, it would be necessary to raise the spindle far enough above the drill to admit the entire length of the workpiece between the chuck and the drill, and then afterwards insert the lpiece into the chuck, possibly a considerable distance.

. The spindle would then have to be moved an equal or greater distance before the drill would be able to act at all. But with the arangement here shown, the workpiece may be inserted laterally without needing to have.

the spindle moved first up and then down so far. A'ring 88 equipped with set screws- 89 is adapted to slide on the sleeve 83 and to, surround the parts 86 and 87 when the latter are assembled, the set screws then clamping these parts upon anything which may be fitted between them. In order to fit.

workpieces of different diameters to the chuck I provide a number of liners 90, one of which is shown in Figures 7, 9 and 10,

In order to insert a long partially subdivided by a single slot 91 in one side, but preferably they are further subdivided by a second slot more or less nearly opposite to the slot 91, and extending through the greater part of the length of the liner, as here shown so as to be compressible, or they may be entirely divided into two parts. At any rate, they serve to center and clamp different workpieces, and are actuated to that end by the set screws 89 of the slidable collar 88.

In order to secure the drill in axial alinement with the spindle 17 and permit vertical adjustment without departure from that alinement, I provide an auxiliary post 92 having a foot 93 which is secured to the base 11 by bolts 94- and nuts 95. There is fitted to slide on this post a split collar 96 having a clamp 97, and being formed as a part of drill into accurate alinement with the spindle.

The sleeve 93 carrying the drill holder and the tub, the post 92, and the work-holding chuck are all adapted to be applied to any existing drill press for which their spe cific dlmensions adapt them; and as I am not restricted to any specific proportion and dimensions, the invention includes in principle attachments applicable to any existing 7 drilling machine for mounting a drill in a stationary position and rotating and feeding the workpiece relatively to' the drill, and in the combination thereof with the accessories already described. Therefore my invention includes an attachment ora set of attachments for drills. further includes the combination in an organized drilling "machine of a stationary drill holder and a rotatable work holder, the drill being held from rotation while operating; and it further includes the combination with such a machine of means for carrying out the drilling operation submerged in liquid, and as well, a means for delivering liquid to the drill in the hole, the

orifice of the hole being at a lower levelv than the point of the drill.

It results from holding the drill stationary and rotating the work that the ,hole

The invention.

produced is bored straight and true without deviation. When the drill -is rotated and is fed into the work, there is always some deviation and the deviation is greater as the drill is more slender and the hole made more deep. In fact the error from this cause is so great that it is impossible to drill accurately centered deep or lon holes in workpieces of small diameter. have discovered that by rotating the work, the opposite tendency results, and the drill point is held in the axis of rotation.

In working upon most metals the tub is supplied with a lubricating and washing fluid which may be a solution in water of washing soda, or a soap solution, or a mixture of these solutions; although-oil or any other liquid may be used in proper circumstances. When the workpiece is fed down over the drill, the. liquid enters the hole with the drill and has the effect both of lubricating the drill and of washing chips from the hole. These effects result whether the circulating pump is operated or not, but the operation of the latter has a more pronounced effect, inasmuch as it causes a stream of the liquid to be delivered from the orifice 69 withfforce enough to penetrate to the point of the drill at the bottom of the hole, and to create'a current having increased efiect in dislodging chips. And the combined action of gravity and the flow of liquid keeps the hole so far clear of chips that it is possible to carry on the cutting of the hole to the limit of penetration of the drillwithout stoppingthe machine and cleaning out thechips. The washing effect is not entirely caused by the current of liquid delivered by the circulating pump, but it is in part caused by the rotation 02E the workpiece.

I have found that as the result of the means and arrangement herein described, I am enabled to perform drilling operations fully three times as rapidly as they can be done in a turning lathe or the ordinary drill press. I can in one continuous operation, without stopping, drill a hole as deep as the entire length of the fluted part of the drill, and the hole thus made is straight and true, whatever may be its diameter' and length, or however great may be the proportion of length to the diameter. The features contributing to the successful accomplishment of these results'are the inverted relation of the drill and work, the fact that the drill is held stationary while the work is rotated, and the provision of a lubricating bath in which the drill and work are submerged; and these features are claimed singly and in combination as parts of the invention. I do not limit my claim to protection, however, to the use of a lubrieating bath as here shown. for, in drilling cast lron, and possibly other materials, I do not use any such bath or make use of lubrication of any sort; The submergence of the work and drill in the bath have the fixed stationary drill holder, a drill secured to said holder and projecting upwardly, a rotatable and endwise movable work holder arranged above said drill and movable in alinement with and toward and from the drill, and a holder containin a bath of liquid enveloping and submerging the drill,

and in which the drilling actions take lace; the liquid in said container being a apted to enter the hole cut by the drill, to wash chips from such hole, and to cool the drill and the work.

2. A drill press comprising a column having a head, a substantially upright work spindle mounted rotatably and with provision for endwise movement on said head, an arm having a slidin engagement with said column but adapte to be rigidly and immovably clamped thereto, projecting laterally from the column, a drillsecured immovably on said arm and projecting toward said spindle in axial alinement therewith, and a guide parallel to the column and adjacent to the outer end of said arm,

constructed to permit adjustment of the arm along the column and at the same time .to so guide the arm that the drill remains prising an arm havinga hub adapted to embrace and be secured to the column of such a press, a tank for liquid secured upon said arm and a holder secured to said arm and projecting upwardly from the bottom of said tank, adapted to hold a drill, the walls of the tank rising above the drill so held, whereby the drill is-submerged in the liquid.

4. In a drill press a laterally projecting arm, a sleeve secured by said arm, a tank connected to the sleeve having in its bottom an opening alined with the sleeve and being packed fluid-tight, a holder fitted leakagetight in said sleeve and adapted to hold a drill, and a' drill mounted by said holder in takes place.

In testimony whereof I have aflixed my signature.

HEN'BICK J. .HJORTH. 

